From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 344F5C433DB for ; Mon, 8 Mar 2021 15:08:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C825865215 for ; Mon, 8 Mar 2021 15:08:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C825865215 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45028 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJHUY-00077V-Q3 for qemu-devel@archiver.kernel.org; Mon, 08 Mar 2021 10:08:18 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:45996) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJHSq-0005TM-SY for qemu-devel@nongnu.org; Mon, 08 Mar 2021 10:06:32 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:35961) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lJHSi-000157-Ue for qemu-devel@nongnu.org; Mon, 08 Mar 2021 10:06:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615215982; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Wl3dKOouZGl+FThlE+OKnTQ+2P3QIIxBLrnML1PGZt8=; b=iDO4DsqDingBSScXMIkfF8gNmKDYrL568YoasC32YWMe3od4E2sq4nyGnvZjO9/rAfzd1O fRGtoQCOcnKEIoO1juvKtC1Uq8u2mu4lgcOoV5uPnSAmAd7Dsvscr9nrIr6Py69VhRO7Ms b//J3BDjU8FaUrMiH3Wl7mNbyYLQYzQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-296-qougcChfPoKfXYDjHK6k9Q-1; Mon, 08 Mar 2021 10:06:21 -0500 X-MC-Unique: qougcChfPoKfXYDjHK6k9Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 752D21084D69; Mon, 8 Mar 2021 15:06:19 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-123.ams2.redhat.com [10.36.113.123]) by smtp.corp.redhat.com (Postfix) with ESMTP id CCB845D9CD; Mon, 8 Mar 2021 15:06:01 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v3 00/12] RAM_NORESERVE, MAP_NORESERVE and hostmem "reserve" property Date: Mon, 8 Mar 2021 16:05:48 +0100 Message-Id: <20210308150600.14440-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.251, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marcel Apfelbaum , Murilo Opsfelder Araujo , Cornelia Huck , Eduardo Habkost , "Michael S. Tsirkin" , Stefan Weil , David Hildenbrand , Richard Henderson , "Dr. David Alan Gilbert" , Peter Xu , Greg Kurz , Halil Pasic , Christian Borntraeger , Stefan Hajnoczi , Igor Mammedov , Thomas Huth , Paolo Bonzini , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Igor Kotrasinski , Juan Quintela Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Some fixes for shared anonymous memory, cleanups previously sent in other context (resizeable allocations), followed by RAM_NORESERVE, implementing it under POSIX using MAP_NORESERVE, and letting users configure it for memory backens using the "reserve" property (default: true). MAP_NORESERVE under Linux has in the context of QEMU an effect on 1) Private/shared anonymous memory -> memory-backend-ram,id=mem0,size=10G 2) Private fd-based mappings -> memory-backend-file,id=mem0,size=10G,mem-path=/dev/shm/0 -> memory-backend-memfd,id=mem0,size=10G 3) Private/shared hugetlb mappings -> memory-backend-memfd,id=mem0,size=10G,hugetlb=on,hugetlbsize=2M With MAP_NORESERVE/"reserve=off", we won't be reserving swap space (1/2) or huge pages (3) for the whole memory region. The target use case is virtio-mem, which dynamically exposes memory inside a large, sparse memory area to the VM. MAP_NORESERVE tells the OS "this mapping might be very sparse". This essentially allows avoiding having to set "/proc/sys/vm/overcommit_memory == 1") when using virtio-mem and also supporting hugetlbfs in the future. virtio-mem currently only supports anonymous memory, in the future we want to also support private memfd, shared file-based and shared hugetlbfs mappings. virtio-mem features I am currently working on that will make it all play together with this work include: 1. Introducing a prealloc option for virtio-mem (e.g., using fallocate() when plugging blocks) to fail nicely when running out of backing storage like huge pages ("prealloc=on"). 2. Handling virtio-mem requests via an iothread to not hold the BQL while populating/preallocating memory ("iothread=X"). 3. Protecting unplugged memory e.g., using userfaultfd ("prot=uffd"). 4. Dynamic reservation of swap space ("reserve=on") 5. Supporting resizable RAM block/memmory regions, such that we won't always expose a large, sparse memory region to the VM. 6. (resizeable allocations / optimized mmap handling when resizing RAM blocks) Based-on: 20210303130916.22553-1-david@redhat.com v2 -> v3: - Renamed "softmmu/physmem: Drop "shared" parameter from ram_block_add()" to "softmmu/physmem: Mark shared anonymous memory RAM_SHARED" and adjusted the description - Added "softmmu/physmem: Fix ram_block_discard_range() to handle shared anonymous memory" - Added "softmmu/physmem: Fix qemu_ram_remap() to handle shared anonymous memory" - Added "util/mmap-alloc: Pass flags instead of separate bools to qemu_ram_mmap()" - "util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE" -- Further tweak code comments -- Handle shared anonymous memory v1 -> v2: - Rebased to upstream and phs_mem_alloc simplifications -- Upsteam added the "map_offset" parameter to many RAM allocation interfaces. - "softmmu/physmem: Drop "shared" parameter from ram_block_add()" -- Use local variable "shared" - "memory: introduce RAM_NORESERVE and wire it up in qemu_ram_mmap()" -- Simplify due to phs_mem_alloc changes - "util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE" -- Add a whole bunch of comments. -- Exclude shared anonymous memory that QEMU doesn't use -- Special-case readonly mappings Cc: Peter Xu Cc: "Michael S. Tsirkin" Cc: Eduardo Habkost Cc: "Dr. David Alan Gilbert" Cc: Richard Henderson Cc: Paolo Bonzini Cc: Igor Mammedov Cc: "Philippe Mathieu-Daudé" Cc: Stefan Hajnoczi Cc: Murilo Opsfelder Araujo Cc: Greg Kurz Cc: Liam Merwick Cc: Marcel Apfelbaum David Hildenbrand (12): softmmu/physmem: Mark shared anonymous memory RAM_SHARED softmmu/physmem: Fix ram_block_discard_range() to handle shared anonymous memory softmmu/physmem: Fix qemu_ram_remap() to handle shared anonymous memory util/mmap-alloc: Factor out calculation of the pagesize for the guard page util/mmap-alloc: Factor out reserving of a memory region to mmap_reserve() util/mmap-alloc: Factor out activating of memory to mmap_activate() softmmu/memory: Pass ram_flags into qemu_ram_alloc_from_fd() softmmu/memory: Pass ram_flags into memory_region_init_ram_shared_nomigrate() util/mmap-alloc: Pass flags instead of separate bools to qemu_ram_mmap() memory: introduce RAM_NORESERVE and wire it up in qemu_ram_mmap() util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE hostmem: Wire up RAM_NORESERVE via "reserve" property backends/hostmem-file.c | 11 +- backends/hostmem-memfd.c | 8 +- backends/hostmem-ram.c | 7 +- backends/hostmem.c | 33 +++ hw/m68k/next-cube.c | 4 +- hw/misc/ivshmem.c | 5 +- include/exec/cpu-common.h | 1 + include/exec/memory.h | 43 ++-- include/exec/ram_addr.h | 9 +- include/qemu/mmap-alloc.h | 20 +- include/qemu/osdep.h | 3 +- include/sysemu/hostmem.h | 2 +- migration/ram.c | 3 +- .../memory-region-housekeeping.cocci | 8 +- softmmu/memory.c | 27 ++- softmmu/physmem.c | 61 +++-- util/mmap-alloc.c | 217 ++++++++++++------ util/oslib-posix.c | 7 +- util/oslib-win32.c | 13 +- 19 files changed, 323 insertions(+), 159 deletions(-) -- 2.29.2